Brake override button
SoaringTheSkies (and others),
why would you suppose that giving the pilot an extra override-button to enable ground spoilers, wheel braking and perhaps thrust reversers, and idling non-reversed engines would make a difference for the better?
Statistics of human error rates are important here.
The error rate of leaving one TL above 20 degress (the exact definition of "at or near idle" was quoted somewhere in this thread) during flare has been shown to be extremely low. Mostly because it makes perfect airmanship sense to select idle thrust at that stage. One just does it without thinking about it. Almost always in these cases, routine is good.
Why would you assume that the error rate of someone inadvertently pressing an override-ground-stop button in the air would be even lower than that, given that it would be an extremely rare situation? Isn't it possible, even likely, that this may happen more often than just once every 10 million flights?
Conversely, what are the chances that the pilot will remember to press it, if he is already in a state of mind that he has forgotten to idle the thrust levers?
Either the "big red button" is on his mind during final approach, remembering that he has to press it when the aircraft won't decelerate, then there is a relatively high chance that someone will press it at the wrong time, plus, it is one more thing to remember, and take-off and landing are the most complex and demanding "normal" phases of a flight as it is.
Or it is not on his mind during final approach, then he might not think of it even when he needs it.
One more emergency procedure to learn and to remember for cases, in which a standard procedure, that is performed every single landing would help?